Interleukin-13 (IL-13) is a cytokine that was first recognized for its effects on B cells and monocytes, where it up-regulates class II expression, promotes IgE class switching and inhibits inflammatory cytokine production. The IL-13 receptor shares the IL-4 receptor alpha chain with the IL-4 receptor. As a result, IL-13 has many similar biological activities to IL-4.
IL-13 inhibits proinflammatory cytokine release and has an anti-inflammatory activity in vivo. IL-13 plays a role in IgE mediated allergic responses and is the central mediator of allergic asthma (Wills-Karp M., Curr. Opin. Pulm. Med., 2003; 9:21-27). In the lung it regulates eosinophilic inflammation, mucus secretion, and airway hyperresponsiveness. In addition to asthma, IL-13 is implicated in the pathogenesis of a large number of diseases (Wynn T A. Annu. Rev. Immunol. 2003. 21:425-456).